Raw lignocellulosic wastes as modifiers in bitumen modification

In this work, the effects of industrial sunflower and cotton stalk agricultural residues as bitumen modifier were studied. The modified bitumens were prepared by adding lignocellulosic wastes in varying ratios. The surface functional groups of bitumens were determined by FT-IR. TGA was performed to investigate their thermal degradation behaviour. The effect of lignocellulosic waste addition on bitumen properties was investigated with thermo-rheological test methods, including viscosity, aging, multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests. The rutting and fatigue behvaior of bitumens was obtained by utilising rheometer. The results showed that bitumen modified with 17% cotton stalk residue exhibited a 46% decrease in penetration, an increase in high-temperature performance grade (PG) from PG 64 to PG 70, a reduction in non-recoverable creep compliance (Jnr) to 0.20kPa−1 (compared to 2.61kPa−1 for the base binder), and an approximately 16% increase in fatigue life at 2.5% strain in the LAS test. However, the improvement in stiffness may also increase energy demand, operational costs.